City of Edmonds Reconsideration XL4420 NV.pdf
May 20, 2014
Michael Clugston, AICP
Associate Planner
City of Edmonds
121 5th Avenue North,
Edmonds, WA. 98020
RE:
Reconsideration of the final decision PLN 2014-0004 for SR104 Safety Grant Mid-
Block Pedestrian Crossing, XL 4420, 20-Night Temporary Construction Hours
Variance
Dear Mr. Clugston:
The Washington State Department of Transportation (WSDOT) requests reconsideration of the
final decision dated May 13, 2014, for noise variance application PLN2014-0004. The
application was submitted to the City of Edmonds for a 20-night temporary noise variance and
$225 was paid to the City of Edmonds for the reconsideration fee.
WSDOT requests reconsideration on the grounds of Edmonds Community Development Code
(ECDC) 20.06.010 A, (2), “Errors of Law or Fact”. WSDOT believes that there are two areas
where a critical error of fact occurred regarding the use of the ambient sound level and
construction sound levels at 500 feet in the final decision.
The assumptions made for, and the use of, the 52 dBA ambient sound levels.
·
Construction sound level at 500 feet
·
Construction Sound Level
The final decision states that a construction source sound level of 80 dBA at 50 feet would
reduce to approximately 55 dBA at 500 feet. However, at a reduction rate of 6 decibels for every
doubling of the distance an 80 dBA source level will reduce to 60 dBA at 500 feet.
Ambient Sound Level
There seems to be some confusion about the background/ambient sound level near the project
area along SR 104. A measured ambient value of 52 dBA collected at night near the closest City
of Edmonds resident to the project at the southeast corner of SR 104 and Pine Street,
approximately 500 feet from the project was provided to the hearing examiner on April 29, 2014
(see Figure 1). The final judgment assumed that 52 dBA was measured adjacent to SR104, so
sound levels 500 feet from the roadway would be 38 dBA. However, since 52 dBA was
Michael Clugston
May 20, 2014
Page 2
measured near the property, not immediately adjacent to SR 104, no additional reductions to the
background sound level are needed to account for distance.
With a measured background of 52 dBA, construction noise is estimated to increase nighttime
sound levels by a maximum of 10 dBA for short periods of time at the nearest property, not
including the proposed noise mitigation. A 10 dBA increase is significantly less than the 20
dBA increase assumed in the final decision, which was based on a background level of 38 dBA
and a construction noise level of 55 dBA.
Further, the proposed construction sound levels should be conservative and do not account for
the additional reductions as the sound travels through the park and over the soft surfaces between
the construction activities and the nearest receiver.
Location of Construction Activity
Location of Nearest Resident
Town of Woodway
Figure 1. Location of construction activity and nearest Edmonds residence.
WSDOT requests temporary relief from the requirements of Washington Administrative Code
(WAC) 173-60-040 and Edmonds City Code (ECC) 5.30 through the variance processes allowed
under ECC 5.30.120 and Edmonds City Development Code (ECDC) 20.85.020. This would
permit WSDOT to conduct construction activities within the City of Edmonds between the hours
of 10:00 P.M. to 7:00 A.M. for 20 non-consecutive nights between June and December 31, 2014.
If you have any questions please contact me at (206) 440-4544
Michael Clugston
May 20, 2014
Page 3
As a representative of the Washington State Department of Transportation (WSDOT) and
acoustics expert I believe the above statements to be true and factual.
Sincerely,
Larry J. Magnoni
Acoustic and Air Quality and Specialist
Washington State Department of Transportation
15700 Dayton Avenue North
Shoreline, WA 98133
206-440-4544
LJM: ljm
Cc: John Chi MS NB82-50
D. Crisman/ S. Esary MS NB82-54
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